(A) Schematic of the expressed recombinant proteins, size exclusion
chromatography trace and SDS-PAGE.
(B) 62B1-1-CIDRα1.7 binds to EPCR with picomolar affinity. A
representative graph from n = 3 independent experiments.
(C) 62B1-1-CIDRα1.7 blocks binding of APC to EPCR. Left: representative
flow cytometry histograms show binding of APC to CHO745-EPCR. Right: percentage
of APC binding to CHO745-EPCR cells in the presence of varying concentrations of
the CIDR domains, relative to APC binding alone. Mean ± SD of n
= 3–5 independent experiments. Ab: Antibody. See Figure S5.
(D) 62B1-1-CIDRα1.7 partially blocks APC-mediated protection from
thrombin-induced barrier disruption of primary human brain endothelial cells
(HBMECs). Left: graph showing the cell index over time. Right: graph showing the
level of APC protection from thrombin-induced barrier disruption in the presence
of 62B1-1-CIDRα1.7 and IT4var31-CIDRα4, relative to APC alone.
Mean ± SD of n = 4 independent experiments
**p<0.01, ***p<0.001 by
the Student’s unpaired, two-tailed t-test.